1. Field of the Invention
The present invention relates to a shaft structure of a liftable screen cover, and in particular to a shaft structure of a screen cover, which has a good rigidity, bears the torsion of the shaft and can be applied to a thin plate screen cover made by press-forming the aluminum alloy or magnesium alloy or a screen cover made by molding carbon fibers.
2. Description of Prior Art
With the development of various kinds of information products, people require that these information products should provide more and more functions with higher quality. Especially, it is an important issue for the manufacturers of notebooks to develop a new product that is more convenient and efficient to use. Such performance is an important index for evaluating the manufacturing technique of the manufactures and determining the leadership in this field of art.
The conventional screen cover of the notebook can be categorized into three kinds according to its material, that is, aluminum alloy, plastics and magnesium-aluminum alloy. The screen cover made of plastics and magnesium-aluminum alloy is a cast and can be formed with reinforcement protrusions. However, for the screen cover made of the aluminum alloy, it is difficult to be formed with reinforcement protrusions because it is a thin screen cover made by press-forming the aluminum alloy. Therefore, such screen cover has a bad rigidity and thus is difficult to bear the torsion of the shaft. If complicated reinforcement structures are additionally provided, it will cause the complication of the whole structure and greatly increase the cost.
Further, when the conventional screen cover is subjected to a twisting force, since the force arm formed by the screen cover is larger and the fulcrum of the shaft is shorter, it is difficult to provide a good rigidity. As a result, deformation and vibration of the screen occur easily. The shaft bears a larger torsion, so that the screw for tightening the shaft will get loosened.
In view of the above, the inventor proposes the present invention to overcome the above problems based on his expert experiences and deliberate researches.